1. Field of the Invention
The present invention relates to a method and apparatus for performing measurement of constituents of blood samples necessitating hemolyzation of said samples. Measurements of that type include determination of oxygen saturation, hemoglobin concentration, erythrocyte electrolyte concentration, etc.
2. Description of the Prior Art
Known apparatuses for measuring the oxygen saturation or hemoglobin concentration in blood samples comprise photometric measuring devices including a light source for emitting light through the blood sample to a photoelectric cell. In order to obtain accurate and reliable measurements it is common practice to hemolyze a blood sample to be measured before introducing it into the apparatus. Such hemolyzation of blood samples was previously normally obtained by cooling them to a temperature below the freezing point or by adding a suitable solvent to the blood samples. It is understood that such separate hemolyzation operation enhances the risk of errors and makes increased demands on the skill of the operator.
In an article entitled "Effects of Hemolysis on Plasma Electrolyte Concentrations of Canine and Porcine Blood" published by Dwight B. Coulter and Larry L. Small in the periodical Cornell Wet. 61 (4), 660, a test has been described wherein a blood sample was divided into two tubes. One of these tubes was exposed to high-frequency sound to produce partial hemolysis, and thereafter the degree of hemolysis and its influence on plasma electrolyte concentrations was determined.